1. Technical Field of the Invention
The present invention relates generally to a fuel pressure sensor/sensor mount assembly in which a fuel pressure sensor is so mounted as to exposed to a high-pressure fuel path through which fuel is supplied to a fuel injector.
2. Background Art
In order to ensure the accuracy in controlling output torque of internal combustion engines and the quantity of exhaust emissions therefrom, it is essential to control a fuel injection mode such as the quantity of fuel to be sprayed from a fuel injector or the injection timing at which the fuel injector starts to spray the fuel. For controlling such a fuel injection mode, there have been proposed techniques for monitoring a change in pressure of the fuel upon spraying thereof from the fuel injector.
Specifically, the time when the pressure of the fuel begins to drop due to the spraying thereof from the fuel injector may be used to determine an actual injection timing at which the fuel has been sprayed actually. The amount of drop in pressure of the fuel arising from the spraying thereof may be used to determine the quantity of fuel sprayed actually from the fuel injector. Such actual observation of the fuel injection mode ensures the desired accuracy in controlling the fuel injection mode.
For instance, in the case where a change in pressure of the fuel arising from the spraying of the fuel from the fuel injector (which will also be referred to as a fuel pressure change below) is measured using a fuel pressure sensor installed directly in a common rail (i.e., a fuel accumulator), it will be somewhat absorbed within the common rail, thus resulting in a decrease in accuracy in determining such a pressure change. In order to alleviate this drawback, Japanese Patent First Publication No. 2000-265892 teaches installation of the fuel pressure sensor in a joint between the common rail and a high-pressure pipe through which the fuel is delivered from the common rail to the fuel injector to measure the fuel pressure change before it is absorbed within the common rail.
In the case of automotive vehicles in which an internal combustion engine is mounted in an engine compartment, it is necessary to install various types of parts such as fuel injectors and a common rail in a small working space within the engine compartment. The workability in such an engine compartment is usually bad. It is, thus, preferable to minimize parts to be installed on or in the engine of the vehicles.
The structure, as disclosed in the above publication, requires the installation of a plurality of fuel pressure sensors in the engine, thus resulting in increased installation processes within the engine compartment.